How to correctly use of jumper cables
and what to watch out for?

For many drivers, the winter season is synonymous with difficult engine starts and dead batteries. Fortunately, a dead battery is not as big a problem as it might seem at first glance. You just need to know how to correctly use the jumper cables and you can revive it quite easily. What are the specific things to watch out for and what can you do to reduce the risk of a dead battery?

Self-discharge of the battery during winter

It is said that cold weather is the most damaging to batteries. In reality, however, it is not entirely true. As we described in our article, batteries suffer the most in high summer temperatures, which cause a faster decrease in their lifespan.

However, during cold winter days, the processes in the battery cannot ensure maximum performance. At temperatures of -20 °C, battery performance can drop by a dizzying 50%. If it is already older and does not have its ideal capacity, it cannot provide enough energy for the starter due to such a drop in performance. And suddenly you simply cannot start the engine.

Praktical tip: If the vehicle is stationary for a long time, self-discharge of the car battery can cause its voltage to drop below a critical value. As a result, you will not be able to start. Therefore, try to start and ride your car properly at least once in a while, or continuously charge the battery from the electrical network using a charger.

Look for signs of a worn battery

Preventing a dead battery is always better than dealing with jumper cables. The voltage will tell you the most about the condition of the battery. Ideally, it should be above 12.6 V. If it is lower, recharge the battery as soon as possible. Otherwise, you risk that it will not provide enough energy to start the engine. Not to mention that it will wear out faster if it is under the ideal voltage level for a longer period of time.

Our advice: Some cars will show you the battery voltage status directly in the on-board computer. If your vehicle does not have this function, get a voltage meter for the 12V socket in the interior, or a more advanced voltmeter that connects directly to the battery poles.

Typical symptoms of a worn battery include subtle flickering of dipped headlights, or fluctuations in the intensity of backlighting in the interior. Difficulty with engine starting is also a clear sign that the battery in your car is probably not in ideal condition.

Starter (jumper) cables – wiring procedure

You got into your car, turned the key and nothing happened? Resp. the starter spins with difficulty, but the engine does not start? In that case, it’s time to use jumper cables.

Don’t try to repeatedly start the engine, when its clearly not working. This will drain the battery even more. Turn the ignition key to the “off” position, call someone with the other car for help, find the battery, clean its contacts and connect the starter cables.

How to connect the starter cables?

Connect the cables when both vehicles have their engines off.

• Connect the red cable to the positive pole of the discharged battery and then connect its opposite end to the positive pole of the battery in the other „donor“ car.
• Connect the black cable to the negative pole of the dead battery and connect its opposite end to the chassis of the other car. Either on any metal part of the engine or body, or directly on the pin that is intended for connecting the starter cable.
• Start the car with a “healthy” battery and let it idle for at least 15 minutes. Then try to start your car. If it doesn’t start after 10 seconds, turn the key to the “off” position and wait another 15-20 minutes.
• When you manage to start it, first disconnect the black cable from your battery and then from the other car. Then disconnect the red cable from the other vehicle and finally from yours.

Important rule: Always connect the black cable in the other vehicle to ground, never to the negative pole of the battery.

Buy suitable jumper cables

Choose starting cables according to the volume of the engine. Up to 2.5-3.0 liters, 400 A cables will suffice, for vehicles with larger engines, 600 A cables are required. You can check both variants in our portfolio.

If jumper cables don’t help and you still can’t start your car, you probably need a new battery. You can find a wide selection of different types in our offer.